DDH is the most common congenital orthopaedic abnormality of the newborn and the one most consistently missed by parents and the most reliably caught by the routine well-child hip exam — when it is done correctly. This is the AAP/POSNA/USPSTF-aligned evidence summary, written for the questions parents, primary-care clinicians, and pediatric orthopaedics referrers actually face.
"Developmental dysplasia of the hip" is the current accepted term, replacing the older "congenital dislocation of the hip" (CDH). The change matters clinically: DDH is a spectrum, not a single binary diagnosis4.
The spectrum runs from:
The "developmental" framing also matters: the abnormality can develop after a normal newborn exam, especially in infants with one or more risk factors and in those exposed to tight lower-extremity swaddling. This is the reason the AAP recommends hip examination at every well-child visit through 12 months, not only at the newborn exam19.
The AAP clinical report and the POSNA evidence-based guideline converge on a selective ultrasound approach. Both endorse the following risk factors as triggers for an imaging workup even in the setting of a normal newborn hip exam12:
The AAP recommends ultrasound between roughly 6 weeks and 4–6 months of age for infants with a positive risk profile and a normal exam. Earlier ultrasound (in the first 4–6 weeks) is technically possible using the Graf method5 but produces a higher false-positive rate driven by neonatal joint laxity that resolves spontaneously. The compromise of 6 weeks to 4–6 months captures the population that needs imaging without over-imaging the population that does not.
Both maneuvers are done on a calm, undressed infant with hips and knees flexed to 90°. The examiner places the third finger over the greater trochanter and the thumb over the inner thigh.
A positive Barlow or Ortolani at any age is an immediate referral to pediatric orthopaedics. Imaging is typically obtained, but the referral does not wait for imaging.
After roughly 3 months of age, the femoral head loses the laxity that produces a palpable clunk, and Barlow/Ortolani sensitivity falls dramatically. The exam pivots to two surrogate findings14:
After 4–6 months of age, ossification of the femoral head reduces the sensitivity of ultrasound; AP pelvis radiograph becomes the imaging study of choice.
For infants and toddlers presenting after walking age (typically >12 months) with an undetected DDH, the exam shifts again:
Late-presenting DDH is harder to treat: closed reduction in a Pavlik harness becomes less reliable after 6 months and is generally unsuccessful after roughly 9–12 months, at which point open reduction with or without femoral or pelvic osteotomy is typically required. The cost of late detection — in surgical complexity, hospital stay, and long-term hip outcome — is the central reason why the routine well-child hip exam is non-negotiable.
The Pavlik harness, used since the mid-20th century, is the standard first-line treatment for confirmed DDH in infants under approximately 6 months of age2. The harness holds the hips in 100°–110° of flexion and approximately 40°–80° of abduction, allowing the femoral head to seat into the acetabulum and the acetabulum to remodel.
Reported success rates depend on age at initiation and on the severity of the dysplasia. Pooled outcomes from POSNA-cited cohorts show:
| Age at initiation | Reported success rate | Notes |
|---|---|---|
| <7 weeks of age, reducible dysplasia | ~85–95% | Highest yield. Atalar et al. and POSNA-cited cohorts8. |
| 7 weeks – 3 months | ~80–90% | Still strongly favored as first-line. |
| 3–6 months | ~60–80% | Closer monitoring required; failure threshold lower. |
| >6 months | <50% | Pavlik typically not recommended; consider closed reduction under anesthesia. |
The two principal complications of the Pavlik harness are avascular necrosis of the femoral head (estimated at 1–5% when properly applied; higher when hip flexion is excessive or duration is prolonged) and femoral nerve palsy (a transient complication usually reversible with harness adjustment or temporary removal). Both are largely preventable with experienced application and serial ultrasound surveillance, which is the reason Pavlik treatment is supervised by pediatric orthopaedics rather than initiated in primary care2.
If the Pavlik harness fails — defined as persistent dislocation after 3–4 weeks of treatment on serial ultrasound — the typical next step is closed reduction under general anesthesia followed by hip spica casting, generally between 6 and 18 months of age. Open reduction (surgical reduction with capsular release) and pelvic or femoral osteotomy are reserved for hips that fail closed reduction or that present late.
The data on long-term outcome favor early detection by a wide margin. Murphy et al. classically documented that adults with untreated mild dysplasia develop hip osteoarthritis at substantially younger ages than the general population, with hip replacement frequently required in the fifth and sixth decades of life7. The Pavlik harness, used early, prevents this trajectory in the great majority of cases.
The AAP clinical report explicitly added tight lower-extremity swaddling as a modifiable risk factor for DDH1. "Tight" here means swaddling that forces the hips and knees into extension and adduction — the opposite of the natural flexion-and-abduction position the developing hip needs.
The current AAP recommendation: when swaddling is used, the lower extremities should be loose enough to allow free hip flexion and abduction (the so-called "hips-healthy" swaddle). The International Hip Dysplasia Institute, AAP, and POSNA all endorse this framing. Parents can swaddle safely for sleep — the swaddle simply needs to leave room for hip movement.
Three honest limitations of the current DDH evidence base deserve mention. First, the optimal sensitivity threshold of selective ultrasound versus universal ultrasound remains debated in some European registries where universal ultrasound is the standard; the AAP/POSNA position reflects North American practice and the USPSTF evidence review13. Second, the exact magnitude of the benefit of early Pavlik harness initiation versus brief observation in mildly unstable hips remains the subject of ongoing trials, with POSNA registries actively studying outcomes. Third, late-presenting DDH after a previously normal newborn exam — the so-called "missed DDH" — is a small but real population whose pathway remains the focus of clinical quality-improvement work in pediatric orthopaedics.
None of these limitations changes the operational standard of care: examine every hip at every well-child visit, image the risk-positive subset, and refer any positive Barlow/Ortolani or limited abduction to pediatric orthopaedics within days, not weeks.
DDH is one of the small set of pediatric conditions in which the cost of missing the diagnosis is enormous (a young-adult hip replacement) and the cost of catching it early is small (a few months in a Pavlik harness). The well-child hip exam — done correctly, repeated at every visit through 12 months, and combined with selective ultrasound for risk-positive infants — is one of the highest-yield clinical examinations in all of primary-care pediatrics.
For parents, the actionable points are: ask which risk factors apply to your infant (breech, family history, female sex), make sure the hip exam is done at every well-child visit, and use the "hips-healthy" swaddle if you swaddle. For clinicians, the actionable points are the AAP/POSNA risk-based ultrasound algorithm, careful preservation of Barlow/Ortolani technique, and a low threshold for orthopaedic referral when the exam is positive.
The Wermom App tracks the AAP Bright Futures well-visit schedule and reminds you which physical-exam findings are expected at each age — including the hip exam. Make sure no well-visit gets skipped.
Open the Wermom AppThis is general health information, not medical advice, and not a substitute for professional care. Educational content evidence-checked against AAP & NHS guidance.
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